cal's -y flag usage

While playing with cal I noticed that using the -y flag along with a
single non-numerical argument or with two arguments would essentially
cause the option to be ignored:

$ cal -y jun
$ cal -y jun 2026
$ cal -y 06 2026

All three commands output the calendar for June 2026 instead of the
entire year. Before I try to patch this, is this the desired/intended
behaviour?

In case a change is desired, would it make sense to split the SYNOPSIS
in the man page into two lines? E.g.:

cal [-jmw] [month] [year]
cal [-jmwy] [year]